Malicious PDF — malware analysis report

Static analysis result for SHA-256 caf4be052d06f0c0…

MALICIOUS

PDF

72.4 KB Created: 2021-09-20 06:27:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f505b50ab79702e81866ee20967f6f31 SHA-1: 1d0dfea4ad3ef7c383d4a09d3b149693453b1fa3 SHA-256: caf4be052d06f0c0f85057329b13cb3388090e380540906f7b116848eb16e0fb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of maliciousness. The document functions as a link farm, containing numerous external URIs that point to compromised CMS upload storage and disposable hosting. These links are likely intended to lead users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://nomylo.ru/uplcv?utm_term=semantic+ui+responsive+navbar PDF link annotation
    • https://www.groupe-coelho.fr/ckfinder/userfiles/files/21785392082.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/161437fed078b9---5735627531.pdfIn PDF document text
    • http://de.ruben.pl/ckfinder/userfiles/files/5592588828.pdfIn PDF document text
    • http://otworz-biuro-podrozy.pl/userfiles/file/17058114943.pdfIn PDF document text
    • https://architektor.ru/uploads/file/kezibedasukaropogiwigu.pdfIn PDF document text
    • http://vigen12.com/userfiles/file/54557406711.pdfIn PDF document text
    • https://giyimkent.formenemlak.com/upload/ckfinder/files/53593640291.pdfIn PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/8d76cd7f4e989a31772237e3596636ce/newuxonuji.pdfIn PDF document text
    • https://hongming-eco.com/userfiles/file/rosowowan.pdfIn PDF document text
    • https://espritgt.com/userfiles/file/94188821450.pdfIn PDF document text
    • http://electriccityusa.com/images/fck_uploads/file/22569573981.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613acbec54653---wijizusozupewuvorawagug.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/55d2b1e828bb994eed6cca9e19ef5037/40025141773.pdfIn PDF document text
    • https://38e5bbdfe8be.gdziezjesc.info/userfiles/file/pekofowenudurovabewuxixin.pdfIn PDF document text
    • http://kperrylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/38860130996.pdfIn PDF document text
    • http://zanethompson.com/userfiles/file/19939165205.pdfIn PDF document text
    • http://webursitet.org/Files/file/3652670704.pdfIn PDF document text
    • http://grandinhr.eu/images/user/file/95079993084.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/3b80f27e40a5c8611c81d32a12cecf3d/59462056974.pdfIn PDF document text
    • https://probidjp.com/ckfinder/userfiles/files/20210917_003108.pdfIn PDF document text
    • http://oris-am.com/editor_up/78964936992.pdfIn PDF document text
    • https://fleuriste79.fr/ckfinder/userfiles/files/70411379813.pdfIn PDF document text
    • http://rideco.hu/upload/file/13419316513.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b9a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9A6 10868 bytes
SHA-256: 00f345936b1ba433c8aeeb6423d8832fd65f071bab185dd0510b167b8ea34c94
font_01_sfnt_off0000d289.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD289 16164 bytes
SHA-256: f23d5bccee11e0f25e72beafed5e2c71797a518006f2d6d19cf866d9ca20dd3f
font_02_sfnt_off0000fc24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC24 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1